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List:       linux-smp
Subject:    Re: Job scheduling in SMP
From:       Felix Rauch <rauch () inf ! ethz ! ch>
Date:       1997-09-18 13:49:18
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On 18 Sep 1997, David [ISO-8859-1] Mentré wrote:
>  You were right. As far as I know, the scheduler try to keep processes
> on the same processor with a small "penalty" if a process moves from a
> processor to another one.

As far as I understand it, this penalty is only small for non-niced
jobs. For jobs with nice 19, it's huge, because the counter-value is
never larger than 2 (maybe it's not even larger than 1, I don't have
the details in memory). For non-niced jobs, the counter value may grow
up to 40, so a penalty of 20 is not too big to change the processor
once in a while.

- Felix
---
Felix Rauch                      | Email: rauch@inf.ethz.ch
Institute for Computer Systems   | Homepage: http://www.cs.inf.ethz.ch/~rauch/
ETH Zentrum / RZ H15             | Phone: ++41 1 632 7489
CH - 8092 Zuerich / Switzerland  | Fax:   ++41 1 632 1307

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